Year	Percent
1960-01-01	12.5350000000000000
1961-01-01	11.9173000000000000
1962-01-01	13.1123000000000000
1963-01-01	14.4443000000000000
1964-01-01	15.1331000000000000
1965-01-01	14.9826000000000000
1966-01-01	13.4301000000000000
1967-01-01	13.3984000000000000
1968-01-01	10.8255000000000000
1969-01-01	9.8605200000000000
1970-01-01	11.1524000000000000
1971-01-01	13.4306000000000000
1972-01-01	15.2475000000000000
1973-01-01	14.0705000000000000
1974-01-01	13.0956000000000000
1975-01-01	8.7325900000000000
1976-01-01	5.3529200000000000
1977-01-01	5.3142700000000000
1978-01-01	4.0168000000000000
1979-01-01	3.0107200000000000
1980-01-01	3.1280799999999997
1981-01-01	3.2937400000000000
1982-01-01	7.1395899999999990
1983-01-01	20.0881000000000000
1984-01-01	33.1824000000000000
1985-01-01	33.2946000000000000
1986-01-01	32.7926000000000000
1987-01-01	36.7808000000000000
1988-01-01	38.2758000000000000
1989-01-01	30.6765000000000000
1990-01-01	20.5603000000000000
1991-01-01	14.8150000000000000
1992-01-01	12.3716000000000000
1993-01-01	12.1503000000000000
1994-01-01	10.5199000000000000
1995-01-01	10.2814000000000000
1996-01-01	9.6718500000000000
1997-01-01	9.1718000000000000
1998-01-01	10.5273000000000000
1999-01-01	13.1928000000000000
2000-01-01	15.1305000000000000
2001-01-01	13.2169000000000000
2002-01-01	22.5645000000000000
2003-01-01	32.8655000000000000
2004-01-01	26.7655000000000000
2005-01-01	21.1234000000000000
2006-01-01	13.2137000000000000
2007-01-01	7.3247500000000000
2008-01-01	8.2360000000000000
2009-01-01	9.3076900000000000
2010-01-01	9.0877400000000000
2011-01-01	9.0083800000000000
2012-01-01	9.0333700000000000
2013-01-01	9.8730300000000000
2014-01-01	10.1343000000000000
2015-01-01	9.8662000000000000
2016-01-01	9.6652100000000000